CN202077249U - Electromagnetic interference preventing and protecting device - Google Patents
Electromagnetic interference preventing and protecting device Download PDFInfo
- Publication number
- CN202077249U CN202077249U CN201120071990XU CN201120071990U CN202077249U CN 202077249 U CN202077249 U CN 202077249U CN 201120071990X U CN201120071990X U CN 201120071990XU CN 201120071990 U CN201120071990 U CN 201120071990U CN 202077249 U CN202077249 U CN 202077249U
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- capacitor
- mode choke
- differential mode
- common mode
- interference
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/40—Arrangements for reducing harmonics
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Abstract
The utility model discloses a circuit capable of preventing electromagnetic interference and used in a lighting system. Due to the fact that a reasonable snubber circuit is designed and a filter is formed by appropriate devices which are calculated and selected, restrain on conducted interference has good effects, and the electromagnetic interference is reduced to the lowest degree.
Description
Technical field
The utility model relates to the electromagnetic interference (EMI) technology, and particularly a kind of circuit specifically is a kind of circuit that is used for the anti-electromagnetic interference capability of illuminator.
Background technology
So-called electromagnetic interference is because the electromagnetic wave that electromagnet phenomenon caused that equipment, transmission channel or systematic function descend.Electromagnetic interference electromagnetic pollution and water pollute, and air pollution is to be called as three of the human society of today to pollute greatly, is subjected to the main source of international community's growing interest, has progressively formed standard and measure, and its limitation causes.
The EMI transfer mode has electromagnetic radiation and conduction to transmit, and radiated interference magnetic field or field coupled electromagnetic wave propagation carry out by power line, and holding wire, ground and other disturb and produce or receive, and two types of differential mode and common modes are arranged.The interference differential mode of the supply power voltage system of between, interference are from a power line, pass an end of power line from the other end back and export, and amplitude is identical, and phase place is opposite.Differential-mode current is flow through, in the stage that the common-mode noise of each power line and voltage magnitude between the ground are equal to mutually, gushed from common mode disturbances current interference source and to be distributed in the ground diffusion capacitance, return through each power line again, power supply is as the important component part of various systems and equipment, it is interference source, be again disturbed person, in order to prevent vicious circle, strengthen the antijamming capability of self when need suppressing the interference of Switching Power Supply, in the low frequency electrodeless lamp illuminating system, rectifier, power switch pipe, fly-wheel diode, transformer, coupling coil etc., these all constitute electromagnetic interference source, and electrodeless lamp itself is just as coil antenna radiated electromagnetic wave outward.
(1) electromagnetic interference of input rectification circuit.
In input circuit, four rectifying tubes of rectifier bridge only could conducting when pulsating voltage surpasses voltage on the input filter capacitor, and electric current is just imported from mains supply, and filter capacitor is charged.So the electric current of input circuit is a pulse character, and the abundant high order harmonic electric current is arranged, not only make circuit produce distortion power, increase the reactive power of circuit, and high-frequency harmonic can produce conducted interference and radiated interference along transmission line, the harm power grid security.
(2) interference of switching circuit.
At switching tube conducting, shutdown moment, its electric current, voltage transient sharply change, the rising edge of electric current, voltage, trailing edge are the very abundant impulse wave of high fdrequency component, be superimposed upon on the shutoff voltage, form the shutoff voltage spike, and the operating frequency of switching tube is very high, forms a broadband electromagnetic interference noise source.
(3) the common mode conducted interference of high frequency transformer.
High frequency transformer is a vitals of realizing store energy, isolation, output, voltage transformation in the switch electrical network, and its leakage inductance and distributed capacitance bring the Electro Magnetic Compatibility of circuit and seriously influence.Common mode disturbances is a kind of interference relative to the earth, thus can in transformer " electric magnetisation and magnetic are given birth to ", not transmit, but transmit by the pale pinkish purple electric capacity between Transformer Winding.Transformer, the HF switch current loop that switching tube and filter capacitor constitute may produce bigger space radiation, forms radiated interference.
The noise jamming of whole system mainly is between 10KHz ~ 30MHz, roughly is divided into three frequency ranges:
(1) 10KHz-0.5MHz: based on differential mode interference;
(2) 0.5MHz-5MHz: differential mode, common mode disturbances are also deposited;
(3) 5MHz-30MHz: based on common mode disturbances.
As seen, the frequency spectrum broad that common mode disturbances accounts for is the main interference of power supply, answers the inhibition of emphasis consideration to common mode disturbances when designing filter.
Summary of the invention
The purpose of this utility model is at the deficiencies in the prior art, designs rational absorption buffer circuit, and electromagnetic interference is reduced to minimum degree.
To achieve these goals, the utility model adopts following technical scheme:
A kind of anti-electromagnetic interference and protector, comprise that fuse and thermistor is characterized in that, also comprise the differential mode filter capacitor of forming by two capacitor C 1, C2, two common mode filtering electric capacity that capacitor C 3, C4 form, a common mode choke T1, the bleeder resistance that differential mode choke T2 and resistance R 1, R2 form; Described capacitor C 1 two ends are connected in the end of common mode choke T1, the other end of common mode choke T1 and 2 parallel connections of described capacitor C; In parallel after described resistance R 1, the R2 series connection with the end of capacitor C 2, differential mode choke T2; The other end with differential mode choke T2 after described capacitor C 3, the C4 parallel connection links, and as the two ends of exporting; Live wire 1 is connected with an end of capacitor C 1 by described fuse, and live wire 3 is connected with the other end of capacitor C 1 by thermistor NTC, and capacitor C 3 is connected with zero line 2 with the junction outconnector of capacitor C 4.
As possibility, it is 1 that described capacitor C 1, C2 power taking are held
, withstand voltage be the ceramic condenser of 400V, capacitor C 3, C4 power taking hold for 3300pF, withstand voltage be the ceramic condenser of 400V, resistance R 1, R2 get 500
Resistance, common mode choke T1 inductance value is got 2mH, differential mode choke T2 inductance value gets 100
H, described choke T1, T2 adopt soft magnetic ferrite as core material.
As possibility, described soft magnetic ferrite can adopt MnZn or NiZn.
Advantage of the present utility model is by designing rational absorption buffer circuit, and the filter that calculates and choose suitable device configuration has effect preferably to the inhibition of conducted interference, and electromagnetic interference is reduced to minimum degree.
Description of drawings
Fig. 1 is the circuit diagram of electromagnetic interface filter circuit;
Fig. 2 is the conducted interference resolution chart;
Fig. 3 is a conducted interference resolution chart behind the use filter.
Embodiment
The utility model is described in further detail below in conjunction with specific embodiment
Circuit design:
Electromagnetic interface filter mainly is made up of inductance and electric capacity, and filter commonly used has C type (pure electric capacity), L type (inductance, an electric capacity), and T type (two inductance, an electric capacity),
Type (inductance, two electric capacity) etc.In general, filter is simple more, and its filter effect will be poor more, selects suitable filters so will take all factors into consideration from aspects such as economy, product standards.
In the electrodeless lamp electronic ballast circuit of the 80W of this circuit design, adopt
Mode filter is the compound hybrid architecture on basis, and as shown in Figure 1, F1 is a fuse, NTC thermistor J1 triple line, C
1, C
2Be differential mode filter capacitor, C
3, C
4Be common mode filtering electric capacity; T
1Be common mode choke, T
2Be the differential mode choke; Resistance R
1, R
2Be bleeder resistance, guarantee that differential mode capacitor fully discharges.C
1, C
2, T
1Common mode interference signal is presented high impedance, and difference mode signal and source current are presented Low ESR, so just guaranteed the decay of source current very littlely, suppressed current noise simultaneously; In like manner, T
2, C
3, C
4The differential mode interference signal is played attenuation.This shows, electromagnetic interface filter is actually a kind of low pass filter, wherein, inductance plays the choked flow effect to radio frequency, and little electric capacity is similar to short circuit to radio frequency, and the interference signal that forces interference source to produce reflects back along the direction that interference source enters, effectively suppress the influence of interference signal, the electromagnetic interference that electric ballast self is produced also plays attenuation simultaneously, guarantees that electrical network is not contaminated, plays the effect of two-way isolation.
The selection of components and parts:
When the electromagnetic interference of the electrodeless lamp electronic ballast of research, because ballast works under the high frequency state, the components and parts that use are not desirable elements, their high frequency parasitic parameter is very big to the influence of disturbing, therefore to take into full account the parasitic parameter of each components and parts, make electromagnetic interface filter arranging effect the best.
(1) selection of electric capacity
The differential mode capacitor device can be used to filtering high frequency differential mode signal, so the differential mode capacitor device will possess higher high frequency characteristics.The network that the high frequency equivalent model of true capacitor is made of electric capacity, equivalent series resistance (ESR) and equivalent series electricity salty (ESL).Inductive component is by lead-in wire and the common decision of capacitance structure, and resistance is that dielectric material itself is intrinsic, and inductive component is the leading indicator that influences frequency characteristic of capacitance.
The resonance frequency f of electric capacity is determined jointly by C and ESL:
If capacitance or equivalent series inductance value are big more, resonance frequency will be low more, and the High frequency filter effect of electric capacity will be poor more, and the electric capacity that EMC Design is used requires resonance to measure height frequently, could play effective filter action wide the getting in the frequency domain scope of trial of strength like this.Equivalent series inductance is except relevant with the kind of capacitor, and the wire length of electric capacity also is an important parameter, and it is long more to go between, and then ESL is big more.Therefore, the raising resonance frequency gets method two: the one, shorten the length that goes between; Another is a kind of selecting for use inductance value less, and ceramic condenser is because self-resonant frequency than higher, thereby is optimal a kind of electric capacity.
The general value of differential mode capacitor device is 1
～5
Between; In addition, except that rated voltage, also can be superimposed with the crest voltage of the various interference sources that exist between the power line on the capacitor, so differential mode capacitor need pass through 1 minute 1500V DC～1700V DC voltage-withstand test, prevent breakdown; The necessary bleeder resistance in parallel in capacitor two ends fully discharges electric capacity, and plug is long charged when preventing the power line plug.The common mode capacitance device belongs to safe electric capacity, and its capacity can not be big, and general value and requires withstand voltage very highly between 2200pF～4700pF, otherwise equipment will leak electricity.
Therefore, differential mode capacitor C1, C2 get 1 in this circuit design
, 400V ceramic condenser; Common mode capacitance is got the ceramic condenser of 3300pF, 400V; Bleeder resistance is two 500
The resistance series connection.
(2) selection of inductance
Inductance in the electromagnetic interface filter has two kinds of differential mode inductance and common mode inductances, owing to have the better performances of the inductance of magnetic core, so generally select the inductor of toroidal core for use, i.e. common mode choke and differential mode choke.Two groups of coils on the common mode choke, around identical to the opposite number of turn, when common mode interference signal flows through, two groups of coils are responded to the flow direction that produces in magnet ring identical, produce stack, thereby make magnetic flux rise rapidly, because ferritic permeability is very high, can obtain very big inductance value, common mode disturbances be played the effect of inhibition.Because the flow direction of differential mode interference signal in common mode choke is opposite, cancel out each other, so common mode choke does not have the effect of inhibition to differential mode interference.The composition of differential mode choke is the same with common mode choke, just the number of turn of two coils with around to all identical, when the differential mode interference signal flows through the differential mode choke, two groups of coils produce the identical magnetic flux of direction in toroidal core, because differential mode interference amplitude equal phase on two groups of coils is opposite, so the magnetic flux that produces superposes mutually, has produced very big inductance, therefore differential mode interference is played the effect of inhibition.In fact, two groups of coils of common mode choke can't be accomplished symmetry completely, so just produced leakage inductance, this is favourable, and little leakage inductance can play the effect that suppresses differential mode interference, is equivalent to a little differential mode inductance.So a lot of people utilize the leakage inductance of common mode inductance to suppress differential mode interference, replace independent differential mode inductance with this, or reduce the inductance value of differential mode inductance, have saved certain space and expense.
The high frequency equivalent circuit of actual inductance except inductance parameters, also has parasitic capacitance and dead resistance, and wherein parasitic capacitance has the greatest impact to the frequency characteristic of inductance.
The inductance operating frequency range enlarges in the frequency range of inductance resonance frequency in actual applications, and key is to reduce parasitic capacitance.The parasitic capacitance and the number of turns, core, around rule and other factors, coil, inductance etc. are as far as possible during the inductance coil of winding, individual layer, and input and output, number of wire turns makes each little electric capacity importantly in the core of coil windings, total capacitance is the parasitic capacitance by two series connection, and the parasitic capacity of total capacity than every section is little.
Choosing also of material for inductor and inductance value will be considered several factors.Therefore at first, the core material wide frequency range will guarantee highest frequency at 1GHz, and more stable magnetic permeability is promptly arranged in very high frequency range, can adopt soft magnetic ferrite as core material, and general ferrite commonly used has two kinds of MnZn and NiZn.The estimation of inductance value will be considered impedance and frequency, and the common mode choke inductance value gets 2
, differential mode choke inductance value gets 100
The low frequency electrodeless lamp electronic ballast of this paper design, when not inserting the EMI filter circuit, utilize EMC300A radiation conducted interference tester to detect, test result as shown in Figure 2, abscissa is a frequency range, ordinate is a noise gain, and red, blue straight line is the noise peak and the mean value gain standard line of regulation, and the noise gain of test product can not surpass the standard of appointment.As can be seen from Figure, do not have under the situation of EMI filter circuit, noise gain exceeds standard more serious, mainly concentrates in 0.06MHz～1MHz band limits, promptly on the harmonious wave point of working frequency points; The above interference signal amplitude of 1MHz is lower.After in electric ballast, inserting the EMI filter circuit, again test, the result as shown in Figure 3, in all band limits of test, the noise that obtains gains frequently and decreases, substantially meet the demands, illustrate that the filter of choosing suitable device configuration by calculating has effect preferably to the inhibition of conducted interference.
The above only is a preferred implementation of the present utility model; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model design; can also make some improvements and modifications, these improvements and modifications also should be considered as in the protection range of the present utility model.
Claims (3)
1. anti-electromagnetic interference and protector, comprise that fuse and thermistor is characterized in that, also comprise the differential mode filter capacitor of forming by two capacitor C 1, C2, two common mode filtering electric capacity that capacitor C 3, C4 form, a common mode choke T1, the bleeder resistance that differential mode choke T2 and resistance R 1, R2 form;
Described capacitor C 1 two ends are connected in the end of common mode choke T1, the other end of common mode choke T1 and 2 parallel connections of described capacitor C; In parallel after described resistance R 1, the R2 series connection with the end of capacitor C 2, differential mode choke T2;
The other end with differential mode choke T2 after described capacitor C 3, the C4 parallel connection links, and as the two ends of exporting;
Live wire 1 is connected with an end of capacitor C 1 by described fuse, and live wire 3 is connected with the other end of capacitor C 1 by thermistor NTC, and capacitor C 3 is connected with zero line 2 with the junction outconnector of capacitor C 4.
2. a kind of anti-electromagnetic interference according to claim 1 and protector is characterized in that it is 1 that described capacitor C 1, C2 power taking are held
, withstand voltage be the ceramic condenser of 400V, capacitor C 3, C4 power taking hold for 3300pF, withstand voltage be the ceramic condenser of 400V, resistance R 1, R2 get 500
Resistance, common mode choke T1 inductance value is got 2mH, differential mode choke T2 inductance value gets 100
H, described choke T1, T2 adopt soft magnetic ferrite as core material.
3. according to any described a kind of anti-electromagnetic interference of claim 1 ~ 2 and protector, it is characterized in that described soft magnetic ferrite adopts MnZn or NiZn.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201120071990XU CN202077249U (en) | 2011-03-18 | 2011-03-18 | Electromagnetic interference preventing and protecting device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201120071990XU CN202077249U (en) | 2011-03-18 | 2011-03-18 | Electromagnetic interference preventing and protecting device |
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| CN202077249U true CN202077249U (en) | 2011-12-14 |
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| CN201120071990XU Expired - Fee Related CN202077249U (en) | 2011-03-18 | 2011-03-18 | Electromagnetic interference preventing and protecting device |
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Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102928777A (en) * | 2012-10-19 | 2013-02-13 | 株洲变流技术国家工程研究中心有限公司 | System and method for load test of diesel generating set |
| TWI460373B (en) * | 2011-12-30 | 2014-11-11 | ||
| CN105072790A (en) * | 2015-07-30 | 2015-11-18 | 王侃 | Ballast used for high frequency electrodeless lamp |
| CN105743338A (en) * | 2016-03-25 | 2016-07-06 | 南京邮电大学 | Electromagnetic loss based common-mode interference suppressor of switching power supply |
| US9640312B2 (en) | 2014-08-19 | 2017-05-02 | General Electric Company | Multi-phase common mode choke |
| CN107196529A (en) * | 2017-06-02 | 2017-09-22 | 杭州中恒电气股份有限公司 | A kind of new individual event power factor correcting converter |
| CN107222115A (en) * | 2017-06-02 | 2017-09-29 | 杭州中恒电气股份有限公司 | A kind of Three phase power factor correcting converter |
| CN107276387A (en) * | 2017-07-03 | 2017-10-20 | 杭州中恒电气股份有限公司 | A kind of new staggeredly totem power factor correcting converter |
| CN107769207A (en) * | 2017-11-21 | 2018-03-06 | 国家电网公司 | Harmonic electric energy regeneration device based on ceramic condenser |
| CN108649816A (en) * | 2018-06-14 | 2018-10-12 | 徐杰 | A kind of current rectifying and wave filtering circuit |
| CN109038474A (en) * | 2018-08-06 | 2018-12-18 | 深圳市凯迪仕智能科技有限公司 | A kind of anti-clutter circuit and anti-interference method |
| CN112303806A (en) * | 2020-10-19 | 2021-02-02 | 青岛海信日立空调系统有限公司 | Communication circuit and air conditioner |
-
2011
- 2011-03-18 CN CN201120071990XU patent/CN202077249U/en not_active Expired - Fee Related
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI460373B (en) * | 2011-12-30 | 2014-11-11 | ||
| CN102928777A (en) * | 2012-10-19 | 2013-02-13 | 株洲变流技术国家工程研究中心有限公司 | System and method for load test of diesel generating set |
| US9640312B2 (en) | 2014-08-19 | 2017-05-02 | General Electric Company | Multi-phase common mode choke |
| CN105072790A (en) * | 2015-07-30 | 2015-11-18 | 王侃 | Ballast used for high frequency electrodeless lamp |
| CN105743338A (en) * | 2016-03-25 | 2016-07-06 | 南京邮电大学 | Electromagnetic loss based common-mode interference suppressor of switching power supply |
| CN107222115A (en) * | 2017-06-02 | 2017-09-29 | 杭州中恒电气股份有限公司 | A kind of Three phase power factor correcting converter |
| CN107196529A (en) * | 2017-06-02 | 2017-09-22 | 杭州中恒电气股份有限公司 | A kind of new individual event power factor correcting converter |
| CN107276387A (en) * | 2017-07-03 | 2017-10-20 | 杭州中恒电气股份有限公司 | A kind of new staggeredly totem power factor correcting converter |
| CN107769207A (en) * | 2017-11-21 | 2018-03-06 | 国家电网公司 | Harmonic electric energy regeneration device based on ceramic condenser |
| CN108649816A (en) * | 2018-06-14 | 2018-10-12 | 徐杰 | A kind of current rectifying and wave filtering circuit |
| CN109038474A (en) * | 2018-08-06 | 2018-12-18 | 深圳市凯迪仕智能科技有限公司 | A kind of anti-clutter circuit and anti-interference method |
| CN112303806A (en) * | 2020-10-19 | 2021-02-02 | 青岛海信日立空调系统有限公司 | Communication circuit and air conditioner |
| CN112303806B (en) * | 2020-10-19 | 2023-11-17 | 青岛海信日立空调系统有限公司 | Communication circuit and air conditioner |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20111214 Termination date: 20140318 |